Honeycomb-type ceramic positive electrode and lithium-ion secondary battery provided with same

Abstract

Provided is a honeycomb-type ceramic positive electrode having a columnar honeycomb structure, having a first end face, a second end face parallel to the first end face, and an outer side face perpendicular to the first end face and the second end face, and also having a plurality of holes extending from the first end face to the second end face. The honeycomb-type ceramic positive electrode is composed of a lithium complex oxide sintered body in which a plurality of primary grains composed of a lithium complex oxide are bonded, and when a central axis of the columnar honeycomb structure parallel to the outer side face or an axis parallel thereto is defined as a z-axis, the plurality of primary grains are oriented in a z-axis direction.

What is claimed is: 
     
         1 . A honeycomb-type ceramic positive electrode with a columnar honeycomb structure having a first end face, a second end face parallel to the first end face, and an outer side face perpendicular to the first end face and the second end face, and also having a plurality of holes extending from the first end face to the second end face,
 wherein the honeycomb-type ceramic positive electrode is composed of a lithium complex oxide sintered body in which a plurality of primary grains composed of a lithium complex oxide are bonded, and   wherein when a central axis of the columnar honeycomb structure parallel to the outer side face or an axis parallel thereto is defined as a z-axis, the plurality of primary grains are oriented in a z-axis direction.   
     
     
         2 . The honeycomb-type ceramic positive electrode according to  claim 1 , wherein the plurality of primary grains are oriented at an average orientation angle of over 0° and 30° or less with respect to the z-axis. 
     
     
         3 . The honeycomb-type ceramic positive electrode according to  claim 1 , wherein the plurality of holes are compartmentalized by a latticed partition wall composed of the lithium complex oxide sintered body. 
     
     
         4 . The honeycomb-type ceramic positive electrode according to  claim 3 , wherein when the columnar honeycomb structure is planarly viewed in the z-axis direction, and one direction of the latticed partition wall is assigned to an x-axis and the other direction to a y-axis, primary grains constituting the partition wall in an x-axis direction are oriented in the x-axis direction, and primary grains constituting the partition wall in a y-axis direction are oriented in the y-axis direction. 
     
     
         5 . The honeycomb-type ceramic positive electrode according to  claim 4 , wherein the plurality of primary grains for every individual partition wall are oriented at an average orientation angle of over 0° and 30° or less with respect to the x-axis or the y-axis. 
     
     
         6 . The honeycomb-type ceramic positive electrode according to  claim 1 , wherein the lithium complex oxide is lithium cobaltate. 
     
     
         7 . A lithium-ion secondary battery, comprising:
 the honeycomb-type ceramic positive electrode according to  claim 1 ;   a plurality of negative electrodes inserted into the plurality of holes and having ends extending out from the first end face or the second end face;   a separator interposed between the honeycomb-type ceramic positive electrode and the negative electrodes;   an electrolytic solution; and   a battery container accommodating the honeycomb-type ceramic positive electrode, the negative electrodes, the separator, and the electrolytic solution.   
     
     
         8 . The lithium-ion secondary battery according to  claim 7 , wherein the negative electrodes comprise carbon. 
     
     
         9 . The lithium-ion secondary battery according to  claim 7 , wherein the separator is a ceramic separator. 
     
     
         10 . The lithium-ion secondary battery according to  claim 7 , wherein the ceramic separator comprises at least one selected from the group consisting of MgO, Al 2 O 3 , ZrO 2 , SiC, Si 3 N 4 , AlN, and cordierite. 
     
     
         11 . The lithium-ion secondary battery according to  claim 7 , further comprising a positive electrode current collecting foil on at least one face of the first end face, the second end face, and the outer side face, excluding a face from which the negative electrodes extend out. 
     
     
         12 . The lithium-ion secondary battery according to  claim 7 , further comprising a negative electrode current collecting foil on the ends of the negative electrodes extending out from the first end face or the second end face.